Fiber-forming interpolymers



Patented Oct. 10, 1944 FIBER-FORMING INTERPOLYMERS Elmore Louis Martin, Wilmington, DeL, assignor to E. I. du Pontde Nemours & Company, Wilmington, Del., a corporation of Delaware No Drawing. Application November 26, 1941, Serial No. 420,591

14 Claims.

Thisinvention relates to polymeric materials and more particularly to polyami'de compositions of improved dyeing properties.

The polyamides with which this invention is concerned are synthetic, high molecular weight, fiber-formirlg polyamides of the general type described in U. S. Patents 2,071,250, 2,071,253 and 2,130,948. These polyamides are usually made by the self-polymerization of a monoaminomono- .carboxylic acid, or by heating a diamine wit a dibasic carboxylic acid until the product has polymerized to the fiber-forming stage, which stage is, not generally reached until the polyamide has an intrinsic viscosity as defined in the last mentioned patent of at least 0.4. The polymers obtained from mixtures of diamine and dibasic carboxylie acid, Or from amide-forming derivatives of these reactants, include a number of polyamides which are particularly valuable as textile fibers because of their high melting points and because filaments of these polyamides can be cold drawn to strong, highly oriented fibers. These fibers, however, are deficient in dyeing properties in that they havea low dye receptivity for dyestufis of the acid, direct and vat classes, and. in that the dyeing accentuates minor non-uniormlties in denier and elongation.

This invention has as an object the prepara-- tion of polyamides which, in addition to the desirable physical properties mentioned above, possess improved dyeing properties. ject is the production. of new and useful polyamide compositions. A still further object is the A further obmanufacture of improved dyed polyamide fibers and fabrics. Otherobiects will appear hereinafter.

These objects are accomplished by interpolymerizing in certain proportions two different polyamide-forming compositions one of which comprises essentially hexamethylenediamine and adipic acid in substantially equimolecular proportions, and the other of which comprises a bifunctional amide-forming reactant containing at least one oxygen atom in the chain separating its amide-forming groups. For convenience the reactant containing the said oxygen atom will be referred to as the hetero oxygen-containing reactant)! be formed into strong oriented fibers which are markedly improved as compared to other diamine-dibasic acid polyamides in dye receptivity and which have high melting points, namely, above 220 C. I have discovered further that the hetero oxygen-containing polyamides, and particularly those obtained with the use of a diamine having at least two hetero oxygen atoms,

have, in addition to improved dye receptivity, improved level dyeing characteristics, i. e., improved uniformity in dyeing. This is a very important property because the minor irregularities nor mally present in yarns and fabrics become evident on dyeing unless the yarns and fabrics have good level dyeing properties.

A diamine which contains at least 2 hetero oxygen atoms in the chain separating the amino groups and which gives outstanding results in the practice of this invention is triglycoldiamine (3,6-dioxa-1,8-octanediamine). This diamine has the formula nmcracmocmcrnocmcnmm Another useful diamine of this type is tetraglycoldiamine mine) of formula These hetero oxygen-containing diamines which are especially useful in the practice of this invention are primary diamines, that is, diamines diamine and dibasic carboxylic acid, can be used as such in preparing the interpolya/mides, but for convenience are preferably used in the form of the diamine-dibasic acid salt.

I have discovered that when this mixture of polyamide-forming compositions is interpolymerized in the proportion by weight, based on the total weight of the named ingredients, of

from 5% to 25% of the polyamide-forming composition containing the hetero oxygen-containing reactant, that the resulting interpolymer can The present interpolymers are prepared by heating the polymer-forming compositions at polyamide-forming temperatures. In the usual practice substantially chemical equivalent amounts of diamine and dibasic acid, or amideforming derivatives thereof,-are heated in the presence or absence of solvent or catalyst, and preferably in the absence of air, at temperatures of from -300 C., and preferably from 200-290 C.,, until a fiber-forming polymer of the desired properties is formed. The reaction (3,6,9-trioxa-1,1l-hendecanediais carried out under conditions which permit the removal of water or other by-product, at least during the last stages of the reaction. As previously indicated, it is desirable to use the two polyamide-forming compositions in the form of their preformed diamine-dibasic acid salts since the salts are easily obtained in pure form and contain substantially equivalent amounts of the diamine and dibasic acid reactants. Thus from 75% to 95%, and preferably from 85% to 95%, of the salt of hexamethylenediamine and adipic acid, namely, hexamethylenediammonium adipate, is reacted with from 5% to 25%, and preferably from 5% to of the salt of the hetero oxygen-containing diamine. The hetero oxygen-containing diamines preferably have the formula. HzNRNH: and the dibasic carboxylic acid or acids used therewith preferably have the formula HOOCR."COOH, in which R and R are divalent organic radicals free from reactive groups and in which R contains at least two hetero atoms of the oxygen family in the chain separating the amino groups. Hydrolysis with hydrochloric acid converts the interpolymers of this invention-into the dibasic acid or acids and the hydro-chlorides of the diamines from which they were derived. Thus in the case of the preferred interpolyamides the hydrolysis products will contain adipic acid, hexamethylenediamine hydrochloride, and the hydrochloride of a diamine containing two hetero oxygenatoms.

The invention is further illustrated by the following examples in which the parts are by weight Exsurtz I 220 C., one hour at 287 C. ,under an atmosphere of nitrogen, and flnallyfor three hours at 287 C. under reduced pressure.

Table I M. P V Manual Intrinsic Cold Salt A Salt B in air) of spina- (polymer viscosity bimy drawing Parts Parts 0.

5 95 243 1. 04 Good. Good. 5 95 243 0. 75 .do Do. 20 80 235 0.71 do Do.

Exsuru: II

- Hexamethylenediammonium adipate and triglycoldiammonium adipate in the proportions indicated in Table II are intimately mixed and polymerized in a closed autoclave in the presence of water and under an atmosphere of nitrogen at 285 C. for three hours. The steam is gradually bled oil until atmospheric pressure is reached and the heating is continued for an additional hour. The polymers are then dried and melt spun into 148 denier-13 filament y ns at assaeev a speed of 3000 ft. per minute. The yarns are subsequently drawn at draw ratios also recorded in Table 11, Draw ratio corresponds to the ratio of the drawn yarn to he undrawn yarn. For example a foot of undrawn yarn drawn to 4.5 feet would then have a draw ratio of 4.5.

Table II Draw Elonga- Bait A Bait B absence Denier of um I ratio tion 4 v "C; 60 950 263 3. 76 37. 7 1s 2 100 900 268 8. 30 35. 0 l6. 5 150 850 264 4. 10 29. 2 16.5

Each polymer was stabilized cent of acetic acid.

Yarns oi the three compositions are dyed with a vat color, an acid color, and a direct color. The receptlvities recorded in Table III, where PTGA with 0.5 moi per refers to polytriglycol adipamide, and PHMA to polyhexamethylene adipamide, show the improvement over that of polyhexamethylene adipamide. tent to which the dye bath was exhausted. These percentages are based on the results obtained by dyeing one gram of yarn in 40 cc. of dye solu- Yarns of each of the lnterpolymers derived from hexamethylenedia'mmonium' adipate with 5, 10, and 15% triglycoldiammonium adipate are drawn so that certain samples difl'er by 4% in draw ratio. For example, a portion of the yarn of the last interpolymer in the table is drawn to original length, and another portion is drawn to 4.10 times its original length. The yarn of 4.28 draw is fed into a single thread circular-knitting machine, and after approximately a two inch section has been knit, the thread is broken and tied to the-fiber drawn to 4.10 its original length and the knitting continued. Such sections are used in level dyeing studies. The interpolymer yams show vast improvement in level dyeing properties when compared to polyhexamethylene adipamide yarns diil'ering similarly in draw ratios. This is particularly marked for acid colors but is also evident for vat and direct colors.

Exams: IV

Following the general procedure described in Example I an interpolymer is made from parts oi hexamethylenediammonium adipate and 15%. of the salt derived from hexamethylenediamine and diglycolic acid. The

a draw ratio of 4.73 and another ara eter Example In and dyed with an acid assumes The percentages represent the expolymer yarn. One portion of the yarn is cold .to

the drawnyerns index No. 430. No color difference is apparent at the junction of the two yarns. This is true also when the acid dye is one of colour index No. 1088. Only a slight color difierence is noticeable when the dye is a direct color of colour index No. 375.

On the other hand, a fabric knit from two polyhexamethylene adipamide yarns exhibiting the mmwnz) 30(CI-Iz) 601cm) 3mm 3,7 -dioxa-1,9-nonanediamine, 3,8-dioxa-1,10-decanediamine, 3,9 dioxa-1,11-hendecanediaminc, 3,10-dioxa 1.12 dodecanediamine, 3,11-dioxa- 1,13-tridecanediamine, 4,7,l-trioxa-1,13-tridecanediamine, 3,12 dioxa 1,14 tetradecanediamine, 3,13-dioxa-1,15-pentadecanediamine, and higher homologs, 4,7-dioxa-1,10-decanediamine,

. 5,8-dioxa-1,12-dodecanediamine, 4,8-di0xa-1,11-

hendecanediamine, and 5,9-dioxa-1,13-tridecanediamine. It is also possible to use diamines containing two oxygen hetero atoms in the chain which contain aromatic or hydroaromatic rings. Examples of such are diphenylolpropane-di-betaaminoethyl ether and 1.4-di-hydroxybenzene-dibeta-aminoethyl ether. However, triglycolcliamine is outstanding.

Examples of dicarboxylic acids which can be used with the hetero oxygen-containing diamines in the reaction with the polyhexamethylene adipamide forming reactants in forming the present interpolymers include such compositions as oxalic acid, malonic acid,- glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, di-glycolic acid, N-methyliminodiacetic acid, piperazine diacetic acid, diphenic acid, and p-phenylenediacetic acid. It is preferred, however, to use adipic acid and particularly to react hexamethylenediammonium adipate with triglycoldiammonium adipate.

While the preferred hetero atom reactants are diamines containing at least two oxygen atoms, reactants containing only one oxygen atom,-or containing the hetero oxygen atom or atoms in the dibasic carboxylic acid can be used in obtaining interpolyamides having improved dye receptivity as compared with polyhexamethylene adipamide. Interpolyamides prepared from hexamethylenediamine, adipic acid, a hetero oxygencontaining diamine and a hetero oxygen-containingdi-bas'ic acid also fall within the scope of the invention. Additional examples of hetero oxygen-containing reactants are 2,2-diamino diethyl ether, 3,3'-diamino dipropyl ether, 5-oxazelaic acid and phenylene dioxyacetic acid. Polymerizable amino acids containing a hetero oxygen atom, e. g., p-aminophenoxy acetic acid, can be used as the hetero oxygen-containing polyamide composition which is reacted with hexamethylenediamine and adipic acid.

The amide-forming derivatives which can be used in place of the dibasic carboxylic acids and diamines mentioned herein include a number of available compounds. Amide-forming derivatives of the dibasic carboxylic acids comprise the monoand di-esters, the anhydrides, the monoand di-amides, the acid halides, and the following compounds in the presence of water: Nitriles,

cyanocarboxylic acids, cyancamides, and cyclic imides. Amide-forming derivatives of the diamines include the carbamates, N-formyl derivatives, and the N,N'-diformy1 derivatives. It is to be understood that reference to a diamine or dibasic carboxylic acid in the claims includes also the amide-forming derivatives thereof.

The interpolymers of this invention have surprisingly greater receptivity for acid, vat, direct, and basic colors than do polyhexamethylene adipamide or similar diamine-dibasic acid polymers. They also have high receptivity for dyestuffs of the cellulose acetate class, e. g., those disclosed in U. S. Patent 2,220,129. The dye receptivity of the present polymers, particularly those prepared with the use of a diamine containing at least two oxygen atoms, approaches, and in some cases exceeds, that of rayon and silk. Furthermore, dyeings on oriented fibers of the interpolymers prepared with the use of diamines containing at least two oxygen atoms are greatly improved in uniformity and levelness, and minor non-uniformities in denier and elongation of the fibers are not accentuated as is the case with polyhexamethylene adipamide, which heretofore has'been one of the most desirable fiber-forming polyamides. The most valuable of the new interpolyamides described herein are those melting above 225 C. When the percentage of hetero oxygen-containing polyamide composition, e. g., triglycoldiammonium adipate, is substantially above 25% there is an objectionable sacrifice in melting point, and the light stability and weathering properties of the polymers decrease rapidly. The presence of substantially less than -5% of hetero oxygen-containing composition does not result in the desired increase of dye receptivity or level dyeing properties.

The polyamides of this invention are of primary interest in the preparation of yarns and fabrics. However, they can. also be used in the applications to which synthetic linear polyamides have been put, e. g.,' bristles, films, and coating, adhesive andmolding compositions. They are of particular value in uses where high dye recep tivity is desired.

The polyamides of this invention can be used in conjunction with other polyamides and/or in conjunction with resins, cellulosic materials, pigments, delusterants, plasticizers, antioxidants, and other modifying agenta' As many apparently widely different embodiments of this invention may be made without departing from the spirit and scope thereof, it is to be understood that I do not limit myself to the specific embodiments thereof except as defined in the appended claims.

I claim:

1. A polymer having higher receptivity for acid dyes than polyhexamethylene adipamide, said polymer comprising the reaction product of 75 to parts by weight of a mixture of hexamethylen'ediamine and adlpic acid in substantially equimolecular proportions and 5 to 25 parts by weight of a polyamide-forming composition comprising a bifunctlonal polyamide-forming reactant containing .at least one oxygen atom in the chain of atoms separating its amide-forming groups, said polyamide-forming composition being selected from the class consisting of (a) mixtures of diamine and dibasic carboxylic acid in substantially equimolecular proportions, and (b) monoaminomonocarboxylic acids.

2. A fiber-forming interpolyamide melting above 220 C. which has a receptivity for acid dyes subsLantially greater than that of polyhexamethylene adipamide and approaching that of silk and which comprises the reaction product of a mixture of hexamethylenediamine, a primary diamine containing at least two oxygen atoms in the chain of atoms separating the amino groups, and dibasic carboxylic acid which is present in equimolecular proportion to said diamines and which comprises adipic acid in amount which is at least in equimolecular proportion to the hexamethylenediamine, the hexamethylenediamine and adipic acid in substantially equimolecular proportion therewith being from 75 to 95 parts by weight of said mixture, and said primary diamine and dibasic carboxylic acid in substantially equimolecular proportions therewith being from to 25 parts by weight 01' said mixture.

3. A fiber-forming polymer which comprises the interpolymerization product of reactants comprising essentially substantially equimolecular proportions of hexamethylenediamine and adipic acid, substantially equimolecular proportions, in amount of from 5% to 25% by weight of the total reactants forming said polymer, of a dibasic carboxylic acid and a primary diamine containing at least two oxygen atoms in the chain separating the amino groups.

4. The polymer set forth in claim 3 in which said dibasic carboxylic acid and primary diamine consists of from 5% to 15% of the total weight of said two polyamide-forming compositions.

5. A fiber-forming polymer which comprises the interpolymerization product of reactants comprising essentially substantially equimolecular proportions of hexamethylenediamine and adipic acid, and substantially equir'nolecular proportions, in amount of from 5% to 25% by weight of the total reactants forming said polymer, of a dibasic carboxylic acid an'd triglycoldiamine.

6. The polymer set forth in claim 5 in which said dibasic carboxylic acid and triglycoldamine consists of from 5% to of the total weight of said two polyamide-forming compositions.

7. A fiber-forming polymer which comprises the interpolymerization product of reactants comprising essentially substantially equimolecular proportions of hexamethylenediamine and adipic acid, and substantially equimolecular proportions, in amount of from 5% to by weight of the total reactants forming said polymer, of adipic acid and triglycoldiamine.

8. A dyed fiber composed of the interpolyamide defined in claim 1.

9. A dyed textile fabric composed oi! the interpolyamide defined in claim 3.

10. A dyed textile fiber composed oi the interpolyamide defined in claim 7.

11. A process for making polymers oi improved dyeing properties which comprises heating at polyamide-iorming temperatures to parts by weight of a composition comprising essentially equimolecular proportions of hexamethylenediamine and adipic acid and 5 to 25 parts by weight of a polyamide-forming composition comprising a bii'uncticnal polyamide-iorming reactant containing at least one oxygen atom in the chain separating its amide-forming groups, a d continuing the interpolymerization reaction until a fiber-forming polymer is obtained, said polyamide-forming composition being selected from the class consisting of ((1) mixtures of diamine and dibasic carboxylic acid in substantially equimolecular proportions, and (b) monoaminomonocarboxylic acids.

12. A process for making fiber-forming polymers oi improved-dyeing properties which comprises heating at polyamide-forming temperatures reactants comprising essentially equimolecular proportions of hexamethylenediamine and adipic acid, and substantially equimolecular proportions, in amount or from 5% to 25% by weight 01' the total reactants forming said polymer, of a dibasic carboxylic acid and a primary diamine containing at least two oxygen atoms in the chain separating the amino groups. and continuing the polymerization reaction until a fiberforming polymer is obtained.

13. A process which comprises heating at polyamide-forming temperatures a mixture of two diamine-dibasic acid salts one of which is hexamethylenediammonium adipete and the other of which is the salt of a dibasic carboxylic acid and a primary diamine containing at least two oxygen atoms in the chain separating the amino groups, said last mentioned salt being from 5% to 25% by weight oi said two salts.

14. 'I'he'process-set forth in claim 11 in which said diamine is triglycoldiamine.

ELMORE LOUIS 

